We propose to develop functional imaging and sensing system combining common-path Fourier-Domain OCT with oxymetry for assisting in neurosurgery. We plan to develop this technology to enhance the safety and efficacy of endoscopic neurosurgery, needle brain biopsies, and anatomical target localization. This subspecialty requires very precise and delicate manipulation of surgical tools through tight spaces with surrounding critical tissues. Therefore, there is high potential value with providing real time intra-operative imaging and oxymetry sensing information which indicates the location of critical anatomical structures such as normal brain-tumor interface, corticospinal tract, and blood vessels, both tumor derived and normal. In order to achieve this objective, the system will have endoscopic micro-optical-fiber sensor that can be fully integrated with existing neurosurgical tools and can measure tissue boundaries relative to surgical tools, blood oxygenation level of surrounding tissues, and identify blood vessels within the tissue volume. We will evaluate the performance of this system for neurosurgery using animal models and human cadaveric specimens. Our proposed approach is novel in several ways. First, this represents the first study of use of a common-path OCT to obtain endoscopic imaging of brain structures and pathological brain abnormalities (in vivo tumor model). Second, this is the first common-path endoscopic sensor integrated with neurosurgical tools in hopes of help guiding endoscopic tools and provides critical tissue avoidance. Third, we will provide first evaluation of the common-path OCT implemented surgical tool for neurosurgery applications. PUBLIC HEALTH RELEVANCE: The proposed work is designed to address and enhance the safety associated with endoscopic neurosurgery by providing surgeons with real-time critical anatomical structure information during surgery.